‘Kakegawa S64’ originated from a hybridization made in November 1998 in Kakegawa, Japan. The female parent was a Calibrachoa ‘Liracashower Blue’ (U.S. Plant Pat. No. 9,885). The male parent was a Calibrachoa breeding line with deep rose colored flowers and mounding habit and short internode length known as 97-1176 (not patented).
In February 1999, F1 seed from this cross was sown and later transplanted outdoors in Kakegawa, Japan. The F1 plants were blue, rose or pink in flower color and ranged from semi-creeping to compact in habit. Three, single-plant selections were made from the F1 plants based on their blue flower color and intercrossed to create an F2 generation. In August 1999, seed from the F2 generation was sown and later transplanted outdoors. F2 plants ranged from extra compact to mounding in habit and all flowers were violet-blue in flower color. Two, single-plant selections were made from the F2 generation based on their extra compact habit and vegetatively propagated. In August 2002, the two selections were evaluated in 9 cm hanging pots in a greenhouse as well as in an open field. One selection was chosen based on the trial.
The selection was further evaluated from new vegetative plants in Salinas, Calif. during 2003. The selection was subsequently named ‘Kakegawa S64’. ‘Kakegawa S64’ was asexually reproduced by stem cuttings in Salinas, Calif. and was determined to reproduce true to type in successive generations of asexual propagation.